Using Electrical Resistance Change to Monitor the Damage in a Thick CFRP Plate Caused by a Dent

Abstract

An impact load on a thick carbon fiber reinforced plastic (CFRP) plate usually causes a dent. The dent results in a decrease of electrical resistance. Our previous paper demonstrated the effect of the dent in the measurement of electrical resistance change of a thick CFRP plate subjected to impact loading. The present paper focuses on the electrical resistance decrease caused by the dent. Numerous FEM analyses were performed, and the relationship between electrical resistance changes and delamination location was constructed, by measuring the response surfaces. Several experiments were conducted and the measured electrical resistance changes were used to predict damage location from the response surfaces. The present study shows that the dent decreases the electrical resistance change ratio even in the adjacent segments, and the electrical resistance changes caused by the dent enable us to monitor the damage location. FEM analyses for a projected area model are sufficient to construct the relationships without resorting to many experiments.

Electrical Resistance Reduction of Laminated Carbon Fiber Reinforced Polymer by Dent Made by Indentation without Cracking

“…Because the method does not require additional sensors, it is applicable to existing CFRP structures. The self-sensing method using electrical resistance change has been applied to detect damage in CFRP structures by many researchers (1)- (20) .…”

“…For a thick CFRP plate, however, the delamination cracking is accompanied by a dent on the surface and the dent caused a decrease in the electrical resistance in the thickness direction of the CFRP plate (17) . The authors' group has revealed a dent monitoring process using the decreased electrical resistance caused by the dent (20) . The mechanism by which the dent reduces the electrical resistance in the thickness direction of the CFRP plate, however, has not been clarified.…”